From 817d760b4dccdae00cbae2283a1d1131fe2bbefe Mon Sep 17 00:00:00 2001
From: sneak <sneak@sneak.berlin>
Date: Thu, 8 Jan 2026 12:20:19 -0800
Subject: [PATCH] Add failing tests for proportional scaling

When only one dimension is provided (e.g., width=400, height=0),
the image should scale proportionally. Currently returns 0x0.
---
 internal/imgcache/processor_test.go | 60 +++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)

diff --git a/internal/imgcache/processor_test.go b/internal/imgcache/processor_test.go
index b0b6135..209b141 100644
--- a/internal/imgcache/processor_test.go
+++ b/internal/imgcache/processor_test.go
@@ -196,6 +196,66 @@ func TestImageProcessor_FitContain(t *testing.T) {
 	}
 }
 
+func TestImageProcessor_ProportionalScale_WidthOnly(t *testing.T) {
+	proc := NewImageProcessor()
+	ctx := context.Background()
+
+	// 800x600 image, request width=400 height=0
+	// Should scale proportionally to 400x300
+	input := createTestJPEG(t, 800, 600)
+
+	req := &ImageRequest{
+		Size:    Size{Width: 400, Height: 0},
+		Format:  FormatJPEG,
+		Quality: 85,
+		FitMode: FitCover,
+	}
+
+	result, err := proc.Process(ctx, bytes.NewReader(input), req)
+	if err != nil {
+		t.Fatalf("Process() error = %v", err)
+	}
+	defer result.Content.Close()
+
+	if result.Width != 400 {
+		t.Errorf("Process() width = %d, want 400", result.Width)
+	}
+
+	if result.Height != 300 {
+		t.Errorf("Process() height = %d, want 300", result.Height)
+	}
+}
+
+func TestImageProcessor_ProportionalScale_HeightOnly(t *testing.T) {
+	proc := NewImageProcessor()
+	ctx := context.Background()
+
+	// 800x600 image, request width=0 height=300
+	// Should scale proportionally to 400x300
+	input := createTestJPEG(t, 800, 600)
+
+	req := &ImageRequest{
+		Size:    Size{Width: 0, Height: 300},
+		Format:  FormatJPEG,
+		Quality: 85,
+		FitMode: FitCover,
+	}
+
+	result, err := proc.Process(ctx, bytes.NewReader(input), req)
+	if err != nil {
+		t.Fatalf("Process() error = %v", err)
+	}
+	defer result.Content.Close()
+
+	if result.Width != 400 {
+		t.Errorf("Process() width = %d, want 400", result.Width)
+	}
+
+	if result.Height != 300 {
+		t.Errorf("Process() height = %d, want 300", result.Height)
+	}
+}
+
 func TestImageProcessor_ProcessPNG(t *testing.T) {
 	proc := NewImageProcessor()
 	ctx := context.Background()